Triggering modes of a nail driver may be classified as single shooting mode and continuous shooting mode. In the continuous shooting mode, the trigger is pressed continuously so as to beat a nail continuously. In the single shooting mode, each time, the trigger is pressed, only one nail is beaten so that the number and positions of nails to be beaten are strictly confined. However, these two ways are not confined by any control device so that the user operates the nail driver by his or her sense. Mistakes occur occasionally.
Thereby, a safety device is added to the nail driver with single and continuous shooting operations, but this prior art still has following disadvantages. Firstly, the components are too complicated to be manufactured easily. The parts are irregular, this make the manufacturing process complicated. It must stop the work for a while to select a shooting mode and to press the safety device so as to make the workers feel uncomfortable in the working process. Namely, the operation cannot be make continuously. 